In recent years, surgeons have been increasingly using surgical staples instead of conventional sutures. Surgical staples and surgical stapling instruments have made many difficult procedures much simpler to perform, and significantly reduced the time required to perform them, thus allowing the patient to spend less time under general anesthesia.
In general, modern surgical stapling instruments for use on internal organs and tissues are comprised of a head containing a cartridge which holds the staples and a mechanism for ejecting the staples out of the cartridge, either sequentially or simultaneously, and driving them through the tissue. Typically, on the other side of the tissues to be stapled, there is an anvil, which deforms the staples into the shape required to hold the tissues together. The head and anvil together form the distal stapling portion of the instrument. There is a proximal portion which houses the actuator mechanism for firing the staples, and the mechanism for bringing the anvil and head to the desired distance and keeping them exactly aligned.
Many types of surgical stapling instruments have been devised for different surgical procedures. Typical designs of basic surgical staplers are disclosed in, for example, U.S. Pat. No. 5,129,570 and U.S. Pat. No. 5,630,541. U.S. Pat. No. 5,452,836 and U.S. Pat. No. 5,603,443 disclose staple designs in which the staple dispensing part and the anvil are separated.
In U.S. Pat. No. 5,403,326, Harrison, et. al. describe apparatus and a method for performing fundoplication of the stomach to the esophagus. The procedure involves introducing three separate devices, an endoscope, an esophageal manipulator, and a stapler through incisions in the skin into the stomach of the subject. The stapler consists of movable jaws at the operating end connected to a handle by an elongated body. One of the jaws contains the staples and the other the anvil. The stapler is introduced into the stomach, positioned with the tissue to be joined between its jaws and the staples are fired by pressing on a button located on the handle.
Bolanus, et. al. disclose in U.S. Pat. No. 5,571,116 another method of performing the fundoplication. In their method, a remotely operable invagination device is introduced transorally into the stomach through the esophagus. After manipulating and clamping the tissue of the fundus and the lower esophagus in the desired manner, a second instrument, a remotely operable fastening device, is introduced. The fastening device consists of a handle containing various levers, etc. to actuate the device, an elongated flexible portion of sufficient length to reach the position at which the operation is to take place, and a stapler at the distal end of the elongated portion.
The stapler is comprised of a cartridge frame, which contains a staple-containing cartridge and the mechanism for ejecting the staples from the cartridge, and an anvil pivotally connected to the distal end of the cartridge frame. To carry out the procedure, the fastening device is inserted with the anvil closed to a point beyond that at which the stapling is to be carried out. The anvil is then allowed to be pivoted open and the fastening device is moved proximally, capturing the tissue to be stapled between the staple cartridge and the anvil. Using the levers on the handle the anvil is again closed clamping the tissue to be fastened. Staple ejectors are then activated driving the staples out of the cartridge, through the tissue, and against the anvil where they are bent into the desired shape. The anvil is again biased open, the fastening device is moved distally to free it from the tissue, the anvil is again closed, and the device is withdrawn.
U.S. Pat. No. 5,197,649 and U.S. Pat. No. 5,395,030 describe surgical staplers that have been developed for connecting the severed edges of tubular tissue such as that of the intestines.
Many other stapler designs are disclosed in the prior art. Many of these are specialized devices that are suitable for performing only the type of procedure for which they have been designed. Most of these are very difficult and time consuming to work with, requiring a great deal of skill to manipulate the tissues and the stapling device.
A basic consideration in the design of all staplers is the fact that it takes a substantial force to bend the staples. Consequently, at the time the staples are fired, the anvil and the head must be clamped rigidly together, or the force will cause them to separate, and the staples will not fully bend. In addition, for the staples to bend to the shape required to hold the tissues together, the anvil and the staple dispensing part must be aligned precisely. Because of these limitations, the distal stapler holding and anvil portions of the device are typically rigidly pivotally connected together in existing staplers. In staplers where the anvil and staple dispensing parts are separate, clamping is done manually at the desired location for stapling, which often necessitates physical manual contact with the tissues to be stapled together.
With current stapling methods, it is impossible to hold the aforementioned parts rigidly together unless they are rigidly or pivotally connected at the time of placement.
It is highly desirable to have a totally flexible connection between the anvil and staple dispensing portions of the instrument. In laparoscopic or open operations, a totally flexible connection will allow stapling in hard-to-reach places. Moreover, a totally flexible stapling instrument could be combined with a flexible endoscope, which will permit the instrument to be passed through natural orifices, such as the mouth, anus, or vagina. Any number of procedures could then be performed without the need to fully anesthetize the patient, and without opening the abdomen. A non-exhaustive list includes: removal of broad-based colonic polyps and small cancers; endoscopic treatment of gastroesophageal reflux disease (GERD), and full thickness biopsies of gastric lesions. All of which are hitherto often performed under the influence of a general anesthetic.
Because of the need to hold the anvil part and the staple dispensing part of the stapler together, a totally flexible connection is not practical, using existing methods.
It is an object of this invention to provide a surgical stapler which overcomes the drawbacks of prior art by providing a totally flexible connection between the staple holder and the anvil parts, at the time of insertion and placement at the surgical site, yet holding the staple dispensing part and the anvil part rigidly together and in precise alignment at the time of the firing of the staples.
It is another purpose of the invention to combine a stapling device made of two separate parts with a flexible endoscope, to achieve an instrument that can be used to endoscopically perform a variety of surgical procedures.
It is a further purpose of this invention to provide a device for performing endoscopic surgical procedures that improves over the devices of prior art in its ease of operation.
It is yet another purpose of the invention to provide a stapling device that is particularly suitable for use in a flexible endoscope for the treatment of GERD by fundoplication.
Other purposes and advantages of this invention will appear as the description proceeds.